Temperature controlled ultrasonic surgical instruments

ABSTRACT

A surgical instrument includes a transducer configured to produce vibrations at a predetermined frequency. An ultrasonic end effector extends along a longitudinal axis and is coupled to the transducer. The ultrasonic end effector comprises an ultrasonic blade and a clamping mechanism. A controller receives a feedback signal from the ultrasonic end effector and the feedback signal is measured by the controller. A lumen is adapted to couple to a pump. The controller is configured to control fluid flow through the lumen based on the feedback signal, and the lumen is located within the ultrasonic end effector.

PRIORITY CLAIM

This application is a divisional application claiming priority under 35U.S.C. §121 to U.S. patent application Ser. No. 12/181,816, entitledTEMPERATURE CONTROLLED ULTRASONIC SURGICAL INSTRUMENTS, filed Jul. 29,2008, which issued on Jun. 2, 2015 as U.S. Pat. No. 9,044,261, whichclaims the benefit of provisional application Ser. No. 60/999,735, filedJul. 31, 2007, which is a conversion of application Ser. No. 11/888,296,filed Jul. 31, 2007. These applications to which Applicant claimspriority are relied upon and incorporated herein by reference.

BACKGROUND

Ultrasonic instruments, including both hollow core and solid coreinstruments, are used for the safe and effective treatment of manymedical conditions. Ultrasonic instruments, and particularly solid coreultrasonic instruments, are advantageous because they may be used to cutand/or coagulate tissue using energy in the form of mechanicalvibrations transmitted to a surgical end effector at ultrasonicfrequencies. Ultrasonic vibrations, when transmitted to tissue atsuitable energy levels and using a suitable end effector, may be used tocut, dissect, coagulate, elevate, or separate tissue. Ultrasonicinstruments utilizing solid core technology are particularlyadvantageous because of the amount of ultrasonic energy that may betransmitted from the ultrasonic transducer, through an ultrasonictransmission waveguide, to the surgical end effector. Such instrumentsmay be used for open procedures or minimally invasive procedures, suchas endoscopic or laparoscopic procedures, wherein the end effector ispassed through a trocar to reach the surgical site.

Activating or exciting the end effector (e.g., cutting blade, ballcoagulator) of such instruments at ultrasonic frequencies induceslongitudinal vibratory movement that generates localized heat withinadjacent tissue, facilitating both cutting and coagulating. Because ofthe nature of ultrasonic instruments, a particular ultrasonicallyactuated end effector may be designed to perform numerous functions,including, for example, cutting and coagulating.

Ultrasonic vibration is induced in the surgical end effector byelectrically exciting a transducer, for example. The transducer may beconstructed of one or more piezoelectric or magnetostrictive elements inthe instrument hand piece. Vibrations generated by the transducersection are transmitted to the surgical end effector via an ultrasonicwaveguide extending from the transducer section to the surgical endeffector. The waveguides and end effectors are designed to resonate atthe same frequency as the transducer. When an end effector is attachedto a transducer the overall system frequency may be the same frequencyas the transducer itself.

The transducer and the end effector may be designed to resonate at twodifferent frequencies and when joined or coupled may resonate at a thirdfrequency. The zero-to-peak amplitude of the longitudinal ultrasonicvibration at the tip, d, of the end effector behaves as a simplesinusoid at the resonant frequency as given by:d=A sin(ωt)where:ω=the radian frequency which equals 2π times the cyclic frequency, f;andA=the zero-to-peak amplitude.The longitudinal excursion is defined as the peak-to-peak (p-t-p)amplitude, which is just twice the amplitude of the sine wave or 2 A.

Solid core ultrasonic surgical instruments may be divided into twotypes, single element end effector devices and multiple-element endeffectors. Single element end effector devices include a variety ofblade types such as ball, hooked, curved, and coagulating shears.Single-element end effector instruments have limited ability to applyblade-to-tissue pressure when the tissue is soft and loosely supported.Substantial pressure may be necessary to effectively couple ultrasonicenergy to the tissue. The inability of a single-element end effector tograsp the tissue results in a further inability to fully coapt tissuesurfaces while applying ultrasonic energy, leading to less-than-desiredhemostasis and tissue joining. Multiple-element end effectors include aclamping mechanism that works in conjunction with the vibrating blade.Ultrasonic clamping coagulators provide an improved ultrasonic surgicalinstrument for cutting/coagulating tissue, particularly loose andunsupported tissue. The clamping mechanism presses the tissue againstthe vibrating ultrasonic blade and applies a compressive or biasingforce against the tissue to achieve faster cutting and hemostatis (e.g.,coagulation) of the tissue with less attenuation of blade motion.

Tissue welding is a technique for closing wounds and vessels and isapplied in many surgical specialties. Tissue welding is a technique forclosing wounds by creating a hemostatic seal in the wounds or vessels aswell as creating strong anastomoses in the tissue. Ultrasonic surgicalinstruments may be employed to achieve hemostatis with minimal lateralthermal damage to the tissue. The hemostatis or anastomoses occursthrough the transfer of mechanical energy to the tissue. Internalcellular friction breaks hydrogen bonds resulting in proteindenaturization. As the proteins are denatured, a sticky coagulum formsand seals small vessels at temperatures below 100° C. Anastomoses occurswhen the effects are prolonged. Thus, the ultrasonic energy in thevibrating blade may be employed to create hemostatic seals in vesselsand adjacent tissues in wounds and to create strong anastomoses intissue. Ultrasonic vibrating single or multiple end effectors, eitheralone or in combination with clamping mechanisms, produce adequatemechanical energy to seal vessels regardless of the temperature of theend effector and/or the tissue. To create strong anastomoses of thetissue, the temperature of the end effector and the tissue should bemaintained below approximately 50° C. to allow for the creation of acoagulum to seal the tissues together without desiccating the tissues.Desiccation occurs through the cavitational effect. As the bladevibrates, it produces an area of transient low pressure at the tip ofthe blade causing fluid inside the cells to vaporize and rupture.Ultrasonic devices have not been successfully employed in tissue weldingapplications because of the need to control the temperature of the endeffector and the tissue to achieve suitable hemostatis and anastomosesto weld tissue together. As the temperature of the end effectorincreases with use, there exists the likelihood that the tissues willdesiccate without forming a proper seal. Conventional ultrasonicinstruments ascertain the tissue state of desiccation as a feedbackmechanism to address temperature control of the ultrasonic end effector.These instruments, however, do not employ the temperature of the endeffector as a feedback mechanism. Therefore, there is a need in the artto monitor and control the temperature of an ultrasonic end effector toeffectively enable the welding of tissues in wounds and/or vessels.

Ultrasonic end effectors are known to build up heat with use. The heatbuild up may be greater when the blade is used in a shears system withhigh coaptation forces. Coaptation in the context of ultrasonic surgicalinstruments refers to the joining together or fitting of two surfaces,such as the edges of a wound, tissue and/or vessel. Standardmethodologies of cooling the end effector blade, such as running fluidthrough the blade while cutting, can have the undesirable effect ofreducing the cutting and coagulating effectiveness of the blade. Thus,there is a need for an ultrasonic end effector blade that is capable ofgenerating adequate heat for hemostatis, coagulation, and/or anastomosestissue but that quickly cools when it is not in use.

SUMMARY

In one general aspect, the various embodiments are directed to asurgical instrument includes a transducer configured to producevibrations at a predetermined frequency. An ultrasonic end effectorextends along a longitudinal axis and is coupled to the transducer. Theultrasonic end effector comprises an ultrasonic blade and a clampingmechanism. A controller receives a feedback signal from the ultrasonicend effector and the feedback signal is measured by the controller. Alumen is adapted to couple to a pump. The controller is configured tocontrol fluid flow through the lumen based on the feedback signal, andthe lumen is located within the ultrasonic end effector.

FIGURES

The novel features of the various embodiments are set forth withparticularity in the appended claims. The various embodiments, however,both as to organization and methods of operation, may best be understoodby reference to the following description, taken in conjunction with theaccompanying drawings as follows.

FIG. 1 illustrates one embodiment of an ultrasonic instrument comprisinga single element end effector.

FIG. 2 illustrates one embodiment of a connection union/joint for anultrasonic instrument.

FIG. 3 illustrates an exploded perspective view of one embodiment of asterile ultrasonic surgical instrument.

FIG. 4 illustrates one embodiment of an ultrasonic instrument comprisinga single element end effector.

FIG. 5 illustrates one embodiment of a connection union/joint for anultrasonic instrument.

FIG. 6 illustrates an exploded perspective view of one embodiment of asterile ultrasonic surgical instrument.

FIG. 7A illustrates one embodiment of a surgical system including asurgical instrument coupled to the ultrasonic generator.

FIG. 7B illustrates one embodiment of a clamping mechanism that may beused with the surgical instrument shown in FIG. 7A.

FIG. 8 illustrates one embodiment of an ultrasonic instrument comprisinga transducer, a end effector, and a full length inner lumen.

FIG. 9 illustrates a distal end of one embodiment of an ultrasonicinstrument comprising a partial length inner lumen.

FIG. 10 illustrates one embodiment of an ultrasonic instrument.

FIG. 11 illustrates a detail view of a distal end of the ultrasonicinstrument shown in FIG. 10.

FIG. 12 illustrates one embodiment of an ultrasonic instrument.

FIG. 13 illustrates a detail view of a distal end of the ultrasonicinstrument shown in FIG. 12.

FIG. 14 illustrates one embodiment of an ultrasonic instrument.

FIG. 15 illustrates a detail view of a distal end of the ultrasonicinstrument shown in FIG. 14.

FIG. 16 illustrates one embodiment of an ultrasonic instrument.

FIG. 17 illustrates a detail view of a distal end of the ultrasonicinstrument shown in FIG. 16.

FIG. 18 illustrates one embodiment of an ultrasonic instrumentcomprising a transducer, a end effector, and a full length sealed innerlumen.

FIG. 19 illustrates a distal end of one embodiment of an ultrasonicinstrument comprising a partial length sealed inner lumen.

FIG. 20 illustrates one embodiment of a tissue welding apparatus.

FIG. 21 illustrates one embodiment of the end effector portion of thetissue welding apparatus shown in FIG. 20.

FIG. 22 is a bottom view of the of the end effector portion of thetissue welding apparatus taken along line 22-22.

FIG. 23 illustrates one embodiment of a multi-element end effectorcomprising an ultrasonic end effector and a clamping mechanism.

FIG. 24 illustrates one embodiment of a multi-element end effectorcomprising an ultrasonic end effector and a clamping mechanism.

FIG. 25 is a diagram illustrating the operation of the ultrasonicinstruments described herein employing an external temperaturemeasurement device.

FIG. 26 is a diagram 1300 illustrating the operation of the ultrasonicinstruments described herein employing a frequency shift temperaturemeasurement technique.

DESCRIPTION

Before explaining the various embodiments in detail, it should be notedthat the embodiments are not limited in its application or use to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings and description. The illustrative embodiments maybe implemented or incorporated in other embodiments, variations andmodifications, and may be practiced or carried out in various ways. Forexample, the surgical instruments and end effector configurationsdisclosed below are illustrative only and not meant to limit the scopeor application thereof. Furthermore, unless otherwise indicated, theterms and expressions employed herein have been chosen for the purposeof describing the illustrative embodiments for the convenience of thereader and are not to limit the scope thereof.

The various embodiments relate, in general, to ultrasonic instrumentswith improved thermal characteristics. In one embodiment, the ultrasonicinstruments provide end effectors with reduced heat build during use.The embodiments include, for example, blades used in a shears systemwith high coaptation forces where the heat build up may be greater.Coaptation in the context of ultrasonic surgical instruments refers tothe joining together or fitting of two surfaces, such as the edges of awound, tissue and/or vessel. The end effector may be cooled by runningfluid through the end effector after cutting tissue when not in use. Oneembodiment provides an ultrasonic blade that is capable of generatingadequate heat for hemostatis, coagulation, and/or anastomoses tissue butthat quickly cools when it is not in use.

In various other embodiments the ultrasonic instruments with improvedthermal characteristics provide improved tissue welding techniques forclosing wounds and vessels as may be applied in many surgicalspecialties. Tissue welding is a technique for closing wounds bycreating a hemostatic seal in the wounds or vessels as well as creatingstrong anastomoses in the tissue. Various embodiments of ultrasonicsurgical instruments provide hemostatis with minimal lateral thermaldamage to the tissue. The hemostatis or anastomoses occurs through thetransfer of mechanical energy to the tissue. Internal cellular frictionbreaks hydrogen bonds resulting in protein denaturization. As theproteins are denatured, a sticky coagulum forms and seals small vesselsat temperatures below 100° Celsius. Anastomoses occurs when the effectsare prolonged. Thus, in various embodiments, the ultrasonic energy inthe vibrating end effector may be employed to create hemostatic seals invessels and adjacent tissues in wounds and to create strong anastomosesin tissue. Other embodiments provide ultrasonic vibrating single ormultiple end effectors, either alone or in combination with clampingmechanisms, to produce suitable mechanical energy to seal vessels withcontrolled temperature end effectors. To create strong anastomoses ofthe tissue, the temperature of the end effector and the tissue should bemaintained or regulated at or below approximately 50° C. to allow forthe creation of a coagulum to seal the tissues together withoutdesiccating the tissues. Desiccation occurs through the cavitationaleffect. As the end effector vibrates, it produces an area of transientlow pressure at the tip of the end effector causing fluid inside thecells to vaporize and rupture. Various embodiments of controlledtemperature ultrasonic devices may be employed in tissue weldingapplications because the temperature of the end effector is effectivelycontrolled to achieve suitable hemostatis and anastomoses to weld tissuetogether. As the temperature of the end effector increases with use, theultrasonic blade and/or clamping mechanism there is measured and coolingfluid is pumped through the blade and/or clamping mechanism. Variousembodiments of the ultrasonic instruments ascertain the tissue state ofdesiccation as a feedback mechanism to address temperature control ofthe ultrasonic end effector. These instruments, employ the temperatureof the end effector as a feedback mechanism to monitor and control thetemperature of an ultrasonic end effector to effectively enable thewelding of tissues in wounds and/or vessels.

Examples of ultrasonic surgical instruments are disclosed in U.S. Pat.Nos. 5,322,055 and 5,954,736 and in combination with ultrasonic endeffectors and surgical instruments disclosed in U.S. Pat. Nos. 6,309,400B2, 6,278,218 B1, 6,283,981 B1, and 6,325,811 B1, for example, areincorporated herein by reference in their entirety. These referencesdisclose ultrasonic surgical instruments and end effector configurationswhere a longitudinal mode of the end effector is excited. Because ofasymmetry or asymmetries, ultrasonic end effectors also may exhibittransverse and/or torsional motion where the characteristic “wavelength”of this non-longitudinal motion is less than that of the generallongitudinal motion of the end effector and its extender portion.Therefore, the wave shape of the non-longitudinal motion will presentnodal positions of transverse/torsional motion along the tissue effectorwhile the net motion of the active end effector along its tissueeffector is non-zero (i.e., will have at least longitudinal motion alongthe length extending from its distal end, an antinode of longitudinalmotion, to the first nodal position of longitudinal motion that isproximal to the tissue effector portion).

Certain embodiments will now be described to provide an overallunderstanding of the principles of the structure, function, manufacture,and use of the devices and methods disclosed herein. One or moreexamples of these embodiments are illustrated in theaccompanying-drawings. Those of ordinary skill in the art willunderstand that the devices and methods specifically described hereinand illustrated in the accompanying drawings are non-limitingembodiments and that the scope of the various embodiments is definedsolely by the claims. The features illustrated or described inconnection with one embodiment may be combined with the features ofother embodiments. Such modifications and variations are intended to beincluded within the scope of the claims.

In one embodiment, the temperature of an ultrasonic end effector may beapproximately determined while in use by measuring the resonantfrequency of the ultrasonic system and correlating variations in the endeffector frequency with the end effector temperature. For example, asthe temperature of the end effector increases, the frequency drops. Thecorrelation between frequency shift or drift due to temperaturevariations may be determined empirically by experimentation or designparameters and programmed into the ultrasonic signal generator or in anelectronic controller coupled to the ultrasonic instrument and/or thegenerator. In one embodiment, a technique measures the frequency of theultrasonic system and utilizes this information to adjust the flow offluid into the surgical area to adjust the temperature of the endeffectors. In another embodiment, the temperature of the end effectormay be determined directly with a temperature sensor. The temperature ofthe end effector may be measured with thermocouple, acoustic sensor, orthermistor type devices embedded within the end effector or theinstrument sheath, allowing a correlation to be made with thetemperature of the end effector. Once the temperature of the endeffector is determined, the end effector may be cooled by flowing lowertemperature fluid on the ultrasonic end effector, through the ultrasonicend effector, or surrounding tissue, keeping them at a predeterminedtemperature.

In various embodiments, the ultrasonic end effector or clampingmechanism may be formed with internal lumens or cannulas such that fluidmay be flowed through the end effector or clamping mechanism at asuitable flow rate necessary to maintain or regulate the end effector ata predetermined temperature. In another embodiment, the fluid may beheated to a predetermined temperature and then flowed through the lumensat a suitable flow rate to transfer heat to the tissue to assist incoagulation or tissue welding.

In another embodiment, a phase change material may be provided in thelumen. The phase change material changes from a solid or liquid phase toa gaseous phase and may be located inside the end effector lumens tocontrol the temperature of the end effector. Expansion of the phasechange material from a solid or liquid phase to a gaseous phase absorbsheat and keeps the end effector at a specified temperature. In yetanother embodiment, the phase change material may act like a heat pipematerial, absorbing heat at the end effector/tissue interface andreleasing the heat away from the interface.

A strong coagulation area, as may be needed in larger lumen tissuewelding applications, may be achieved by maintaining the temperature ofthe end effector surface at a point between where coagulation of thetissue can occur but where desiccation of the tissue does not occur.Lowering the temperature of the ultrasonic end effector enables the endeffector to contact the tissue for a longer period. This allows for boththe side of the tissue in contact with the end effector and the side incontact with the coaptation pad to form viable coagulation zones, thusimproving the weld strength of the tissue. In another embodiment, thesame end effector cooling fluid may be routed through a coaptation padto increase the temperature of the tissue on the side opposing the endeffector.

Thus, in one embodiment, the temperature of the ultrasonic end effectormay be controlled by employing end effector temperature measurement as afeedback mechanism and infusing water or another cooling fluid into theend effector to maintain or control the temperature of the end effector.Infusing water at a specified temperature keeps the end effector at thattemperature and absorbs excess energy from the system that wouldotherwise desiccate the tissue. The end effector temperature may bemeasured using frequency change of the system or by direct measurementof the end effector sheath temperature. End effector temperature may becontrolled by infusing a cooling fluid through the end effector. Thecooling fluid may be employed to cool the ultrasonic end effector and toheat the coaptation pad side of the instrument.

Irrigation lumens formed within the body of an ultrasonic end effectorhave been employed in ultrasonic aspirators such as ultrasonic surgicalaspirators (CUSA®) produced by CAVITRON®, for example. The lumens act asfluidic conduits to provide relatively constant irrigation to the targetsite. In one embodiment, a end effector irrigation lumen may befluidically coupled to an irrigation pump that is programmed forintermittent activation. The ultrasonic end effector may be used fortissue cutting and/or hemostasis (e.g., coagulation). During thisprocess, the pump remains in a no-flow condition. Once the tissue loadis removed from the end effector, the ultrasonic signal generator orcontroller senses the no tissue load condition and then operates thepump either continuously or intermittently to supply cooling fluid tothe end effector for a specified amount of time or until the endeffector reaches a predetermined temperature. In one embodiment, theultrasonic signal generator or a controller may be adapted andconfigured to sense the end effector temperature by a referredmeasurement of system frequency and fluid may be supplied to the endeffector until the end effector reaches a predetermined temperature.

In another embodiment, the ultrasonic signal generator or a controllermay be adapted and configured to control the supply of fluid to the endeffector for a specified amount of time after the user discontinuesusing the end effector. This embodiment in combination with thetemperature measuring embodiment may be employed to cool the endeffector to a specified temperature. In yet another embodiment, acooling fluid may be fed or supplied either from a lumen formed withinthe end effector sheath or from a fluid flow port attached to thesheath. Either of these methods would be suitable for spraying fluidover the exterior of the end effector to control the temperaturethereof.

FIG. 1 illustrates one embodiment of an ultrasonic instrument 10comprising a single element end effector. One embodiment of theultrasonic instrument 10 comprises an ultrasonic transducer 14, a handpiece assembly 60 comprising a hand piece housing 16, and anultrasonically actuatable single element end effector or ultrasonicallyactuatable end effector 50. The end effector 50 may be, for example, ablade, ball coagulator, graspers, cutters, staplers, clip appliers,access devices, drug/gene therapy devices, ultrasound, microwave, RF,High Intensity Focused Ultrasound (HIFU), and/or laser devices. Theultrasonic instrument 10 is coupled to an ultrasonic signal generator12. The generator 12 comprises a control system integral with thegenerator 12, a power switch 8, and a triggering mechanism 44. The powerswitch 8 controls the electrical power to the generator 12, and whenactivated by the triggering mechanism 44, the generator 12 providesenergy to drive an acoustic assembly 24 of the surgical system 10 at apredetermined frequency and to drive the end effector 50 at apredetermined excursion level. The generator 12 drives or excites theacoustic assembly 24 at any suitable resonant frequency of the acousticassembly 24. The ultrasonic transducer 14, which is known as a “Langevinstack”, generally includes a transduction portion 18, a first resonatorportion or end-bell 20, and a second resonator portion or fore-bell 22,and ancillary components. The total construction of these components isa resonator. The ultrasonic transducer 14 is preferably an integralnumber of one-half wavelengths (nλ/2 where “n” is any positive integer,e.g., n=1, 2, 3 . . . ; and where the wavelength “λ” is the wavelengthof a pre-selected or operating longitudinal vibration frequency f_(o) ofthe acoustic assembly) in length as will be described in more detaillater. The acoustic assembly 24 includes the ultrasonic transducer 14,an adapter 26, a velocity transformer 28, and a surface 30. In variousembodiments, the transducer 14 may be constructed of one or morepiezoelectric or magnetostrictive elements.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the hand piece assembly60. Thus, the end effector 50 is distal with respect to the moreproximal hand piece assembly 60. It will be further appreciated that,for convenience and clarity, spatial terms such as “top” and “bottom”also are used herein with respect to the clinician gripping the handpiece assembly 60. However, surgical instruments are used in manyorientations and positions, and these terms are not intended to belimiting and absolute.

The distal end of the end-bell 20 is connected to the proximal end ofthe transduction portion 18, and the proximal end of the fore-bell 22 isconnected to the distal end of the transduction portion 18. Thefore-bell 22 and the end-bell 20 have a length determined by a number ofvariables, including the thickness of the transduction portion 18, thedensity and modulus of elasticity of the material used to manufacturethe end-bell 20 and the fore-bell 22, and the resonant frequency of theultrasonic transducer 14. The fore-bell 22 may be tapered inwardly fromits proximal end to its distal end to amplify the ultrasonic vibrationamplitude as the velocity transformer 28, or alternately may have noamplification. A suitable vibrational frequency range may be about 20 Hzto 120 kHz and a well-suited vibrational frequency range may be about30-100 kHz. A suitable operational vibrational frequency may beapproximately 55.5 kHz, for example.

Piezoelectric elements 32 may be fabricated from any suitable material,such as, for example, lead zirconate-titanate, lead meta-niobate, leadtitanate, barium titanate, or other piezoelectric ceramic material. Eachof positive electrodes 34, negative electrodes 36, and the piezoelectricelements 32 has a bore extending through the center. The positive andnegative electrodes 34 and 36 are electrically coupled to wires 38 and40, respectively. The wires 38 and 40 are encased within a cable 42 andelectrically connectable to the ultrasonic signal generator 12 of theultrasonic instrument 10.

The generator 12 also has a power line 6 for insertion in anelectro-surgical unit or conventional electrical outlet. It iscontemplated that the generator 12 also can be powered by a directcurrent (DC) source, such as a battery. The generator 12 may compriseany suitable generator. The ultrasonic transducer 14 of the acousticassembly 24 converts the electrical signal from the ultrasonic signalgenerator 12 into mechanical energy that results in primarily a standingwave of longitudinal vibratory motion of the ultrasonic transducer 24and the end effector 50 at ultrasonic frequencies. In anotherembodiment, the vibratory motion of the ultrasonic transducer may act ina different direction. For example, the vibratory motion may comprise alocal longitudinal component of a more complicated motion of the tip ofthe ultrasonic instrument 10. A suitable generator is available as modelnumber GEN04, from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. Whenthe acoustic assembly 24 is energized, a vibratory motion standing waveis generated through the acoustic assembly 24. The amplitude of thevibratory motion at any point along the acoustic assembly 24 dependsupon the location along the acoustic assembly 24 at which the vibratorymotion is measured. A minimum or zero crossing in the vibratory motionstanding wave is generally referred to as a node (i.e., where motion isminimal), and an absolute value maximum or peak in the standing wave isgenerally referred to as an anti-node (i.e., where motion is maximal).The distance between an anti-node and its nearest node is one-quarterwavelength (λ/4).

The wires 38 and 40 transmit an electrical signal from the ultrasonicsignal generator 12 to the positive electrodes 34 and the negativeelectrodes 36. The piezoelectric elements 32 are energized by theelectrical signal supplied from the ultrasonic signal generator 12 inresponse to an actuator or triggering mechanism 44, such as a footswitch, for example, to produce an acoustic standing wave in theacoustic assembly 24. The electrical signal causes disturbances in thepiezoelectric elements 32 in the form of repeated small displacementsresulting in large alternating compression and tension forces within thematerial. The repeated small displacements cause the piezoelectricelements 32 to expand and contract in a continuous manner along the axisof the voltage gradient, producing longitudinal waves of ultrasonicenergy. The ultrasonic energy is transmitted through the acousticassembly 24 to the single element end effector 50, such as the blade,via a transmission component or an ultrasonic transmission waveguide104.

For the acoustic assembly 24 to deliver energy to the single element endeffector 50, all components of the acoustic assembly 24 must beacoustically coupled to the end effector 50. The distal end of theultrasonic transducer 14 may be acoustically coupled at the surface 30to the proximal end of the ultrasonic transmission waveguide 104 by athreaded connection such as a cannulated threaded stud 48.

The components of the acoustic assembly 24 are preferably acousticallytuned such that the length of any assembly is an integral number ofone-half wavelengths (nλ/2), where the wavelength λ is the wavelength ofa pre-selected or operating longitudinal vibration drive frequency f_(d)of the acoustic assembly 24, and where n is any positive integer. It isalso contemplated that the acoustic assembly 24 may incorporate anysuitable arrangement of acoustic elements.

The length of the end effector 50 may be substantially equal to anintegral multiple of one-half wavelengths (nλ/2). A distal end 52 of theend effector 50 may be disposed near an antinode in order to provide themaximum longitudinal excursion of the distal end 52. When the transducerassembly is energized, the distal end 52 of the end effector 50 may beconfigured to move in the range of, for example, approximately 10 to 500microns peak-to-peak, and preferably in the range of about 30 to 150microns at a predetermined vibrational frequency of 55 kHz, for example.

The end effector 50 may comprise an inner lumen 68 extendinglongitudinally to receive and conduct fluid to a target site. The targetsite may be the cutting, coagulating, or tissue welding site, forexample. The lumen 68 is in fluid communication with (e.g., isfluidically coupled to) a fluid pump 64. In various embodiments, thefluid pump 64 and the ultrasonic signal generator 12 may be combined ina single integral unit. In the embodiment, illustrated in FIG. 1, theultrasonic transmission waveguide 104 comprises a longitudinallyextending lumen 58 formed therein and the ultrasonic transducer 14comprises a lumen 56 formed through the fore bell 20, the end bell 22,the velocity transformer 28, and the coupling stud or bolt 35. The bolt35 also comprises a lumen 55 substantially aligned with the lumen 56.The ultrasonic transmission waveguide 104 comprises a longitudinallyprojecting attachment post 54 at a proximal end to couple to the surface30 of the ultrasonic transmission waveguide 104 by a cannulated threadedconnection such as the cannulated threaded stud 48. The ultrasonictransmission waveguide 104 is coupled to the velocity transformer 28portion of the ultrasonic transducer 14 by the cannulated threaded stud48. The fluid pump 64 is fluidically coupled to the lumens 56, 58, and68 such that fluid is communicated from the fluid pump 64 to the endeffector 50 and it emanates into the target site from the distal end 52of the end effector 50. In one embodiment, the fluid may be heated orcooled to a predetermined temperature by a fluid temperature regulator65 (e.g., a heater, a chiller, a temperature bath, or any of variousmechanisms for maintaining a temperature) before it is pumped into thelumens 56, 58, and 68 by the fluid pump 64.

The piezoelectric elements 32 may be held in compression between thefirst and second resonators 20 and 22 by the bolt 35. The bolt 35 mayhave a head, a shank, and a threaded distal end. The bolt 35 may beinserted from the proximal end of the first resonator 92 through thebores of the first resonator 20, the electrodes 34 and 36, and thepiezoelectric elements 32. The threaded distal end of the bolt 35 isscrewed into a threaded bore in the proximal end of second resonator 22.The bolt 35 can be fabricated from steel, titanium, aluminum, or othersuitable material. In various embodiments, the bolt 35 may be fabricatedfrom Ti6Al4V Titanium, Ti6-4 Titanium, and most preferably from 4037 lowalloy steel.

The end effector 50 may be coupled to the ultrasonic transmissionwaveguide 104. The end effector 50 and the ultrasonic transmissionwaveguide 104 as illustrated are formed as a single unit constructionfrom a material suitable for transmission of ultrasonic energy. Examplesof such materials include Ti6Al4V (an alloy of Titanium includingAluminum and Vanadium), Aluminum, Stainless Steel, or other suitablematerials. Alternately, the end effector 50 may be separable (and ofdiffering composition) from the ultrasonic transmission waveguide 104,and coupled by, for example, a stud, weld, glue, quick connect, or othersuitable known methods. The length of the ultrasonic transmissionwaveguide 104 may be substantially equal to an integral number ofone-half wavelengths (nλ/2), for example. The ultrasonic transmissionwaveguide 104 may be preferably fabricated from a solid core shaftconstructed out of material suitable to propagate ultrasonic energyefficiently, such as the titanium alloy discussed above (i.e., Ti6Al4V)or any suitable aluminum alloy, or other alloys, for example.

In one embodiment, the ultrasonic transmission waveguide 104 includes aplurality of stabilizing silicone rings or compliant supports positionedat a plurality of nodes (not shown). The silicone rings dampenundesirable vibration and isolate the ultrasonic energy from an outersheath (not shown) assuring the flow of ultrasonic energy in alongitudinal direction to the distal end 52 of the end effector 50 withmaximum efficiency.

The outer sheath protects a user of the ultrasonic surgical instrument10 and a patient from the ultrasonic vibrations of the ultrasonictransmission waveguide 104. The sheath generally includes a hub and anelongated tubular member. The tubular member is attached to the hub andhas an opening extending longitudinally therethrough. The sheath isthreaded onto the distal end of the housing 16. The ultrasonictransmission waveguide 104 extends through the opening of the tubularmember and the silicone rings isolate the ultrasonic transmissionwaveguide 104 from the outer sheath. The outer sheath may be attached tothe waveguide 104 with an isolator pin. The hole in the waveguide 104may occur nominally at a displacement. The waveguide 104 may screw orsnap onto the hand piece assembly 60 by the cannulated threaded stud 48.Flat portions on the hub may allow the assembly to be torqued to arequired level.

The hub of the sheath is preferably constructed from plastic and thetubular member is fabricated from stainless steel. Alternatively, theultrasonic transmission waveguide 104 may comprise polymeric materialsurrounding it to isolate it from outside contact.

The distal end of the ultrasonic transmission waveguide 104 may becoupled to the proximal end of the end effector 50 by an internalcannulated threaded connection, preferably at or near an antinode. It iscontemplated that the end effector 50 may be attached to the ultrasonictransmission waveguide 104 by any suitable means, such as a welded jointor the like. Although the end effector 50 may be detachable from theultrasonic transmission waveguide 104, it is also contemplated that thesingle element end effector 50 (e.g., a blade) and the ultrasonictransmission waveguide 104 may be formed as a single unitary piece.

FIG. 2 illustrates one embodiment of a connection union/joint 70 for anultrasonic instrument. The connection union/joint 70 may be formedbetween the attachment post 54 of the ultrasonic transmission waveguide104 and the surface 30 of the velocity transformer 28 at the distal endof the acoustic assembly 24. The proximal end of the attachment post 54comprises a female threaded substantially cylindrical surface 66 toreceive a portion of the cannulated threaded stud 48 therein. The distalend of the velocity transformer 28 also may comprise a female threadedsubstantially cylindrical surface 69 to receive a portion of thecannulated threaded stud 48. The surfaces 66, 69 are substantiallycircumferentially and longitudinally aligned. The lumens 56 and 58 arefluidically coupled to the fluid pump 64 at a proximal end and to theend effector 50 lumen 68 at a distal end (FIG. 1).

FIG. 3 illustrates an exploded perspective view of one embodiment of asterile ultrasonic surgical instrument 80. The ultrasonic surgicalinstrument 80 may be employed in the above-described ultrasonicinstrument 10. However, as described herein, those of ordinary skill inthe art will understand that the various embodiments of the ultrasonicsurgical instruments disclosed herein as well as any equivalentstructures thereof could conceivably be effectively used in connectionwith other known ultrasonic surgical instruments without departing fromthe scope thereof. Thus, the protection afforded to the variousultrasonic surgical end effector embodiments disclosed herein should notbe limited to use only in connection with the embodiments of theultrasonic surgical instrument described above. The ultrasonic surgicalinstrument 80 may be sterilized by methods known in the art such as, forexample, gamma radiation sterilization, Ethelyne Oxide processes,autoclaving, soaking in sterilization liquid, or other known processes.

In the embodiment illustrated in FIG. 3, the ultrasonic surgicalinstrument 80 comprises an ultrasonic transmission assembly 82. Theultrasonic transmission assembly 82 comprises the ultrasonicallyactuatable end effector 50, the ultrasonic transmission waveguide 104,the projecting attachment post 54, and an outer sheath 84. Theultrasonic transmission waveguide 104 comprises the longitudinallyextending lumen 58 and the end effector comprises the longitudinallyextending lumen 68. The end effector 50 and the ultrasonic transmissionwaveguide 104 may be formed as a unitary piece from a material suitablefor transmission of ultrasonic energy such as, for example, Ti6Al4V (analloy of Titanium including Aluminum and Vanadium), Aluminum, StainlessSteel, or other known materials. Alternately, the end effector 50 may beformed such that it is detachable or separable (and of differingcomposition) from the ultrasonic transmission waveguide 104, and coupledthereto by, a stud, weld, glue, quick connect, or other known methods,for example. In either implementation, the longitudinally extendinglumens 58 and 68 are substantially aligned. The length of the ultrasonictransmission waveguide 104 may be substantially equal to an integralnumber of one-half wavelengths (nλ/2), for example. The ultrasonictransmission waveguide 104 may be fabricated from a solid core shaftconstructed out of material that propagates ultrasonic energyefficiently, such as titanium alloy (i.e., Ti6Al4V) or an aluminumalloy, for example.

In the embodiment illustrated in FIG. 3, the ultrasonic transmissionwaveguide 104 is positioned in the outer sheath 84 by a mounting O-ring108 and a sealing ring 110. One or more additional dampers or supportmembers (not shown) also may be included along the ultrasonictransmission waveguide 104. The ultrasonic transmission waveguide 104 isaffixed to the outer sheath 84 by the isolator pin 112 that passesthrough mounting holes 114 in the outer sheath 84 and a mounting hole116 in the ultrasonic transmission waveguide 104.

FIG. 4 illustrates one embodiment of an ultrasonic instrument 100comprising a single element end effector. One embodiment of theultrasonic instrument 100 comprises an ultrasonic transducer 114, thehand piece assembly 60 comprising the hand piece housing 16, and theultrasonically actuatable single element end effector or ultrasonicallyactuatable end effector 50. The ultrasonic instrument 100 is coupled tothe ultrasonic signal generator 12. The ultrasonic transducer 114, whichis known as a “Langevin stack”, generally includes a transductionportion 18, a first resonator portion or end-bell 20, and a secondresonator portion or fore-bell 122, and ancillary components such ascoupling stud or bolt 135, for example. The construction and operationof the bolt 135 is substantially similar to the bolt 35 discussed aboveexcept it is formed as a solid piece, without the central lumen 55. Thetotal construction of these components is a resonator. The ultrasonictransducer 114 is preferably an integral number of one-half wavelengths(nλ/2) in length as will be described in more detail later. An acousticassembly 124 includes the ultrasonic transducer 114, an adapter 26, avelocity transformer 128, and a surface 30. The operation of theultrasonic transducer 114 is substantially similar to that describedabove with reference to FIG. 1 and for convenience and clarity is notrepeated herein. In contrast to the ultrasonic transducer 14 shown inFIG. 1, the ultrasonic transducer 114 shown in FIG. 4 does not includelumens formed therein. Rather, as described in more detail below, aninlet port 73 may be formed in an attachment post 74 or along theultrasonic transmission waveguide 105 that is fluidically coupled to alumen 72 extending longitudinally within the attachment post 74 and anultrasonic waveguide 105. The lumen 72 is fluidically coupled to thelumen 68 formed in the end effector 50. The lumen 72 may besubstantially aligned with the lumen 68 formed in the end effector 50.

As previously described, the end effector 50 comprises an inner lumen 68extending longitudinally to receive and transfer fluid to through theend effector 50 or to a target site. The target site may be the cutting,coagulating, or tissue welding site, for example. The lumen 68 isfluidically coupled to the fluid pump 64. In the embodiment, illustratedin FIG. 4, the ultrasonic transmission waveguide 105 comprises a lumen72 formed longitudinally therein. The ultrasonic transmission waveguide105 comprises a longitudinally projecting attachment post 74 at aproximal end to couple to the surface 30 of the ultrasonic transmissionwaveguide 105 by a threaded connection such as a threaded stud 148. Theultrasonic transmission waveguide 105 is coupled to the velocitytransformer 128 portion of the ultrasonic transducer 114 by the threadedstud 148. The fluid pump 64 is fluidically coupled to the lumens 72 and68 via the inlet port 73 formed in the attachment post 74 such thatfluid is communicated from the fluid pump 64 to the end effector 50 andit emanates into the target site from the distal end 52 of the endeffector 50. In one embodiment, the fluid may be heated by the fluidtemperature regulator 65 before it is pumped into the lumens 72 and 68by the fluid pump 64.

FIG. 5 illustrates one embodiment of a connection union/joint 170 for anultrasonic instrument. The connection union/joint 170 may be formedbetween the attachment post 74 of the ultrasonic transmission waveguide105 and the surface 30 of the velocity transformer 128 at the distal endof the acoustic assembly 124. The proximal end of the attachment post 74comprises a female threaded substantially cylindrical surface 66 toreceive a portion of the threaded stud 148 therein. The distal end ofthe velocity transformer 128 also may comprise a female threadedsubstantially cylindrical surface 69 to receive a portion of thethreaded stud 148. The surfaces 66, 69 are substantiallycircumferentially and longitudinally aligned. The lumen 72 isfluidically coupled to the fluid pump 64 via the inlet port 73 at aproximal end and is coupled to the end effector 50 lumen 68 at a distalend (FIG. 4).

FIG. 6 illustrates an exploded perspective view of one embodiment of asterile ultrasonic surgical instrument 81. The ultrasonic surgicalinstrument 81 may be employed in the above-described ultrasonicinstrument 100. However, as described herein, those of ordinary skill inthe art will understand that the various embodiments of the ultrasonicsurgical instruments disclosed herein as well as any equivalentstructures thereof could conceivably be effectively used in connectionwith other known ultrasonic surgical instruments without departing fromthe scope thereof. Thus, the protection afforded to the variousultrasonic surgical end effector embodiments disclosed herein should notbe limited to use only in connection with the embodiments of theultrasonic surgical instrument described above. The ultrasonic surgicalinstrument 81 may be sterilized by methods known in the art such as, forexample, gamma radiation sterilization, Ethelyne Oxide processes,autoclaving, soaking in sterilization liquid, or other known processes.

In the embodiment illustrated in FIG. 6, the ultrasonic surgicalinstrument 81 comprises an ultrasonic transmission assembly 83. Theultrasonic transmission assembly 83 comprises the ultrasonicallyactuatable end effector 50, the ultrasonic transmission waveguide 105,the projecting attachment post 74, and an outer sheath 85. Theultrasonic transmission waveguide 105 comprises the longitudinallyextending lumen 72 and the end effector comprises the longitudinallyextending lumen 68. The sheath 85 comprises an opening 87 to receive afluid line in the inlet port 73. The end effector 50 and the ultrasonictransmission waveguide 105 may be formed as a unitary piece from amaterial suitable for transmission of ultrasonic energy such as, forexample, Ti6Al4V (an alloy of Titanium including Aluminum and Vanadium),Aluminum, Stainless Steel, or other known materials. Alternately, theend effector 50 may be formed such that it is detachable or separable(and of differing composition) from the ultrasonic transmissionwaveguide 105, and coupled thereto by, a stud, weld, glue, quickconnect, or other known methods, for example. In either implementation,the longitudinally extending lumens 72 and 68 are substantially aligned.The length of the ultrasonic transmission waveguide 105 may besubstantially equal to an integral number of one-half wavelengths(nλ/2), for example. The ultrasonic transmission waveguide 105 may befabricated from a solid core shaft constructed out of material thatpropagates ultrasonic energy efficiently, such as titanium alloy (i.e.,Ti6Al4V) or an aluminum alloy, for example.

In the embodiment illustrated in FIG. 6, the ultrasonic transmissionwaveguide 105 is positioned in the outer sheath 85 by a mounting O-ring108 and a sealing ring 110. One or more additional dampers or supportmembers (not shown) also may be included along the ultrasonictransmission waveguide 105. The ultrasonic transmission waveguide 105 isaffixed to the outer sheath 85 by the isolator pin 112 that passesthrough mounting holes 114 in the outer sheath 85 and a mounting hole116 in the ultrasonic transmission waveguide 104.

FIG. 7A illustrates one embodiment of a surgical system 200 including asurgical instrument 202 coupled to the ultrasonic generator 12. In theembodiment illustrated in FIG. 7A, the ultrasonic surgical instrument202 is an ultrasonic clamp coagulator. The surgical instrument 202includes an ultrasonic drive unit 204. The ultrasonic drive unit 204 maycomprise the ultrasonic transducer 14 (FIG. 1) or the ultrasonictransducer 114 (FIG. 4) based on the implementation. Therefore, forconvenience and clarity, the description of the operation the ultrasonicdrive unit 204 will not be repeated herein. The ultrasonic transducer ofthe ultrasonic drive unit 204 is coupled to an ultrasonic end effector206 of the surgical instrument 202. Together these elements provide anacoustic assembly of the surgical system 200, with the acoustic assemblyproviding ultrasonic energy for surgical procedures when powered by thegenerator 12. It will be noted that, in some applications, theultrasonic drive unit 204 may be referred to as a “hand piece assembly”because the surgical instrument 202 of the surgical system 200 isconfigured such that a clinician grasps and manipulates the ultrasonicdrive unit 204 during various procedures and operations. The ultrasonicinstrument 202 may comprise a scissors-like grip arrangement whichfacilitates positioning and manipulation of the instrument 202 apartfrom manipulation of the ultrasonic drive unit 204.

As previously discussed, the generator 12 of the surgical system 200sends an electrical signal through a cable 42 at a selected excursion,frequency, and phase determined by a control system of the generator 12.As previously discussed, the signal causes one or more piezoelectricelements of the acoustic assembly of the surgical instrument 202 toexpand and contract along a longitudinal axis, thereby converting theelectrical energy into longitudinal mechanical motion. The mechanicalmotion results in longitudinal waves of ultrasonic energy that propagatethrough the acoustic assembly in an acoustic standing wave to vibratethe acoustic assembly at a selected frequency and excursion. The endeffector 206 is placed in contact with tissue of the patient to transferthe ultrasonic energy to the tissue. For example, a distal portion orblade 208 of the end effector 206 may be placed in contact with thetissue. As further described below, a surgical tool, such as, a jaw orclamping mechanism 210, may be utilized to press the tissue against theblade 208.

As the end effector 206 couples to the tissue, thermal energy or heat isgenerated as a result of friction, acoustic absorption, and viscouslosses within the tissue. The heat is sufficient to break proteinhydrogen bonds, causing the highly structured protein (e.g., collagenand muscle protein) to denature (e.g., become less organized). As theproteins are denatured, a sticky coagulum forms to seal or coagulatesmall blood vessels. Deep coagulation of larger blood vessels resultswhen the effect is prolonged.

The transfer of the ultrasonic energy to the tissue causes other effectsincluding mechanical tearing, cutting, cavitation, cell disruption, andemulsification. The amount of cutting as well as the degree ofcoagulation obtained varies with the excursion of the end effector 206,the frequency of vibration, the amount of pressure applied by the user,the sharpness of the blade 208, and the coupling between the endeffector 206 and the tissue.

As previously discussed, the generator 12 comprises a control systemintegral with the generator 12, a power switch 8, and a triggeringmechanism 44. The power switch 8 controls the electrical power to thegenerator 12, and when activated by the triggering mechanism 44, thegenerator 12 provides energy to drive the acoustic assembly of thesurgical system 200 at a predetermined frequency and to drive the endeffector 180 at a predetermined excursion level. The generator 12 drivesor excites the acoustic assembly at any suitable resonant frequency ofthe acoustic assembly.

When the generator 12 is activated via the triggering mechanism 44,electrical energy in the form of an electrical signal is continuouslyapplied by the generator 12 to a transducer stack or assembly of theacoustic assembly 24 (FIG. 1) or 124 (FIG. 4) as previously discussed. Aphase-locked loop in the control system of the generator 12 monitorsfeedback from the acoustic assembly. The phase lock loop adjusts thefrequency of the electrical signal transmitted by the generator 12 tomatch of the acoustic assembly including the tissue load. In addition, asecond feedback loop in the control system maintains the currentamplitude of the electrical signal supplied to the acoustic assembly ata pre-selected constant level in order to achieve substantially constantexcursion at the end effector 206 of the acoustic assembly. Tissue loadcan be detected and provided as a feedback signal indicative of anoperational state of the ultrasonic blade 208.

The electrical signal supplied to the acoustic assembly will cause thedistal end of the end effector 206, e.g., the blade 208, to vibratelongitudinally in the range of, for example, approximately 20 kHz to 250kHz, and preferably in the range of about 54 kHz to 56 kHz, and mostpreferably at about 55.5 kHz. The excursion of the vibrations at theblade 208 can be controlled by, for example, controlling the amplitudeof the electrical signal applied to the transducer assembly of theacoustic assembly by the generator 12.

As previously discussed, the triggering mechanism 44 of the generator 12allows a user to activate the generator 12 so that electrical energy maybe continuously supplied to the acoustic assembly. The triggeringmechanism 44 may comprise a foot activated switch that is detachablycoupled or attached to the generator 12 by a cable or cord.Alternatively, the triggering mechanism 44 can be configured as a handswitch incorporated in the ultrasonic drive unit 204 to allow thegenerator 12 to be activated by a user.

The generator 12 also has a power line 6 for insertion in anelectro-surgical unit or conventional electrical outlet. It iscontemplated that the generator 12 also can be powered by a directcurrent (DC) source, such as a battery. The generator 12 may compriseany suitable generator, such as Model No. GEN04 available from EthiconEndo-Surgery, Inc.

The ultrasonic drive unit 204 of the surgical instrument 202 includes amulti-piece housing 212 adapted to isolate the operator from thevibrations of the acoustic assembly. The drive unit housing 212 can beshaped to be held by a user in a conventional manner, but it iscontemplated that the clamp coagulator instrument ultrasonic instrument202 is principally grasped and manipulated by a pistol-like arrangement214 provided by a housing of the apparatus. While the multi-piecehousing 212 is illustrated, the housing 212 may comprise a single orunitary component.

The ultrasonic drive unit 204 housing 212 generally comprises a proximalend, a distal end, and a cavity extending longitudinally therein. Thedistal end of the housing 212 includes an opening 216 configured toallow the acoustic assembly of the surgical system 200 to extendtherethrough, and the proximal end of the housing 212 is coupled to thegenerator 12 by the cable 42. The cable 42 may include ducts, conduits,or lumens 218 to allow cooling fluid to be introduced to and to cool theend effector 206.

The housing 212 of the ultrasonic drive unit 204 may be constructed froma durable plastic, such as ULTEM®. It is also contemplated that thehousing 212 may alternatively be made from a variety of materialsincluding other plastics (e.g., liquid crystal polymer [LCP], nylon, orpolycarbonate). A suitable ultrasonic drive unit 204 is Model No. HP054,available from Ethicon Endo-Surgery, Inc.

The acoustic assembly of the surgical instrument 200 generally includesa first acoustic portion and a second acoustic portion. The firstacoustic portion may be carried by the ultrasonic drive unit 204, andthe second acoustic portion in the form of an end effector 206 iscarried by the ultrasonic clamp coagulator ultrasonic instrument 202.The distal end of the first acoustic portion is operatively coupled tothe proximal end of the second acoustic portion, preferably by athreaded connection.

In the embodiment illustrated in FIG. 7A, the first acoustic portioncomprises the transducer stack or assembly 14 (FIG. 1) or 114 (FIG. 4)and the respective velocity transformers 28, 128 and mounting surface30, and the second acoustic portion includes the end effector 206. Theend effector 206 may in turn comprise a transmission component, orwaveguide 220, as well as a distal portion, or the blade 208, forinterfacing with tissue. The waveguide 220 may be substantially similarto the waveguide 104 (FIGS. 1 and 2) or 105 (FIGS. 4 and 5).

As previously discussed, the components of the acoustic assembly may beacoustically tuned such that the length of each component is an integralnumber of one-half wavelengths (nλ/2). It is also contemplated that theacoustic assembly may incorporate any suitable arrangement of acousticelements.

The transducer assembly of the acoustic assembly converts the electricalsignal from the generator 12 into mechanical energy that results inlongitudinal vibratory motion of the end effector 206 at ultrasonicfrequencies. When the acoustic assembly is energized, a vibratory motionstanding wave is generated through the acoustic assembly. The excursionof the vibratory motion at any point along the acoustic assembly dependson the location along the acoustic assembly at which the vibratorymotion is measured. A minimum or zero crossing in the vibratory motionstanding wave is generally referred to as a node (e.g., where motion isusually minimal), and an absolute value maximum or peak in the standingwave is generally referred to as an anti-node. The distance between ananti-node and its nearest node is one-quarter wavelength (λ/4).

As previously described with reference to FIGS. 1 and 4, thepiezoelectric elements 32 may be energized in response to the electricalsignal supplied from the generator 12 to produce an acoustic standingwave in the acoustic assembly 24, 124. The electrical signal causes anelectromagnetic field across the piezoelectric elements 32, causing thepiezoelectric elements 32 to expand and contract in a continuous manneralong the longitudinal axis of the voltage gradient, producing highfrequency longitudinal waves of ultrasonic energy. The ultrasonic energyis transmitted through the acoustic assembly 24, 124 to the end effector206.

The mounting device 84 of the acoustic assembly has a proximal end, adistal end, and may have a length substantially equal to an integralnumber of one-half wavelengths (nλ/2). The proximal end of the mountingdevice 84 may be axially aligned and coupled to the distal end of thesecond resonator 94 by an internal threaded connection near ananti-node. It is also contemplated that the mounting device 84 may beattached to the second resonator 94 by any suitable means, and thesecond resonator 94 and mounting device 84 may be formed as a single orunitary component.

The proximal end of the clamp coagulator ultrasonic surgical instrument202 preferably receives and is fitted to the distal end of theultrasonic drive unit 204 by insertion of the drive unit 204 into thehousing 212. The clamp coagulator ultrasonic surgical instrument 202 maybe attached to and removed from the ultrasonic drive unit 204 as a unit.The clamp coagulator ultrasonic surgical instrument 202 may be disposedof after a single use.

The clamp coagulator ultrasonic surgical instrument 202 may comprise anelongated or endoscopic portion 222. When the present apparatus isconfigured for endoscopic use, the construction can be dimensioned suchthat the elongated portion 222 has an outside diameter of about 5.5 mm.The elongated portion 222 of the clamp coagulator ultrasonic surgicalinstrument 202 may extend substantially orthogonally from the apparatushousing 204. The elongated portion 222 can be selectively rotated withrespect to the housing 204 as described below. The elongated portion 222may include an outer tubular member or sheath 224, an inner tubularactuating member 226, and the second acoustic portion of the acousticsystem in the form of an end effector 206 including a blade 208. Theouter sheath 224, the actuating member 226, and the end effector 206 maybe joined together for indexed rotation as a unit (together withultrasonic drive unit 204) relative to housing 212 by way of a rotationknob 228.

The end effector 206 may include a waveguide 220. The waveguide 220 maybe substantially semi-flexible. It will be recognized that,alternatively, the waveguide 220 can be substantially rigid or maycomprise a flexible wire. The waveguide 220 may be configured to amplifythe mechanical vibrations transmitted through the waveguide 220 to theblade 208 as is well known in the art. The waveguide 220 may furthercomprise features to control the gain of the longitudinal vibrationalong the waveguide 220 and features to tune the waveguide 220 to theresonant frequency of the system.

It will be recognized that the blade 208 may comprise any suitablecross-sectional dimension. For example, the blade 208 may have asubstantially uniform cross-section or the blade 208 may be tapered atvarious sections or may be tapered along its entire length. According tovarious embodiments, the blade 208 may be mechanically sharp formed witha cutting edge or may be mechanically blunt. The distal end of the blade208 is disposed near an anti-node in order to tune the acoustic assemblyto a preferred resonant frequency f_(o) when the acoustic assembly isnot loaded by tissue. When the transducer assembly is energized, thedistal end of the blade 208 is configured to move longitudinally in therange of, for example, approximately 10-500 microns peak-to-peak, andpreferably in the range of about 10 to about 100 microns at apredetermined vibrational frequency f_(o). In accordance with theillustrated embodiment, the blade 208 may be cylindrical for cooperationwith the associated clamping mechanism of the clamp coagulatorultrasonic surgical instrument 202. The waveguide 220 and the blade 208may receive suitable surface treatment, as is known in the art.

FIG. 7B illustrates one embodiment of a clamping mechanism 210 that maybe used with the surgical instrument shown in FIG. 7A. The clampingmechanism 210 may be configured for cooperative action with the blade208 of the end effector 206. The clamping mechanism 208 includes apivotally movable clamp arm 230, which is pivotally connected at thedistal end thereof to the distal end of outer tubular sheath 224. Theclamp arm 230 includes a clamp arm tissue pad 232, preferably formedfrom TEFLON® or other suitable low-friction material, which is mountedfor cooperation with the blade 208, with pivotal movement of the clamparm 230 positioning the clamp pad 232 in substantially parallelrelationship to, and in contact with, the blade 208. By thisconstruction, tissue to be clamped is grasped between the tissue pad 232and the blade 208. The tissue pad 232 may be provided with asawtooth-like configuration including a plurality of axially spaced,proximally extending gripping teeth 234 to enhance the gripping oftissue in cooperation with the blade 208.

Pivotal movement of the clamp arm 230 with respect to the blade 208 iseffected by the provision of at least one, and preferably a pair oflever portions 236 of the clamp arm 230 at the proximal end thereof. Thelever portions 236 are positioned on respective opposite sides of theend effector 206 and the blade 208, and are in operative engagement witha drive portion 238 of the reciprocal actuating member 226. Reciprocalmovement of the actuating member 226, relative to the outer tubularsheath 224 and the end effector 206, thereby effects pivotal movement ofthe clamp arm 230 relative to the blade 208. The lever portions 236 canbe respectively positioned in a pair of openings defined by the driveportion 238, or otherwise suitably mechanically coupled therewith,whereby reciprocal movement of the actuating member 226 acts through thedrive portion 238 and lever portions 236 to pivot the clamp arm 230.

The ultrasonic waveguide 220 and the blade 208 may comprise an innerlumen 240 extending longitudinally to receive and transfer fluid asindicated by arrow 242 to a target site. The target site may be thecutting, coagulating, or tissue welding site, for example. The lumen 240is fluidically coupled to the fluid pump 64. In the embodiment,illustrated in FIGS. 7A, 7B, if the ultrasonic drive unit 204 isimplemented as the ultrasonic transducer 14 shown in FIG. 1, the lumen240 extends from the ultrasonic transmission waveguide 220 through theattachment post 54, the cannulated threaded stud 48, the velocitytransformer 28, the end bell 22, the fore bell 20, the end bell 22, theultrasonic transducer 14, and the coupling stud or bolt 35 and isfluidically coupled to the fluid pump 64 through one or more lumens 218.In the embodiment illustrated in FIGS. 7A, 7B, the ultrasonic drive unit204 is implemented as the ultrasonic transducer 114 shown in FIG. 4.Accordingly, the lumen 240 extends from the ultrasonic transmissionwaveguide 220 through the attachment post 74 and is fluidically coupledto the fluid pump 64 through the input port 73. The fluid pump 64 isfluidically coupled to the lumen 240 such that fluid is communicatedfrom the fluid pump 64 to the blade 208 and it emanates as shown byarrow 242 into the target site from the distal end of the blade 208. Inone embodiment, the fluid may be chilled, heated, or the temperaturethereof may be otherwise controlled by the fluid temperature regulator65 before it is pumped into the lumen 240 by the fluid pump 64. In oneembodiment, the fluid may be coupled through the lumen 240 to a fluidicchannel 244 formed in the clamp arm 230. Accordingly, the fluid can flowthrough the clamp arm 230 and emanates from the channel 244 as indicatedby arrow 246.

FIG. 8 illustrates one embodiment of an ultrasonic instrument 300comprising a transducer 316, a end effector 324, and a full length innerlumen 308. An ultrasonic waveguide 320 is coupled to the ultrasonictransducer 316 at a coupling connection or union/joint 328. The couplingconnection 328 is substantially similar to the coupling connection 70discussed with reference to FIG. 2. The full length inner lumen 308extends from a proximal end of the instrument 300 to a distal end of theend effector 324 through the transducer 316 and the end effector 324.The lumen 308 extends longitudinally through several sections of theinstrument 300. The lumen 308 extends through a bore 312 formed throughpiezoelectric elements 310 and a bore 314 formed through an ultrasonictransducer 316. The inner lumen 308 further extends through a bore 318formed within an ultrasonic waveguide 320 and further extends through abore 322 formed within a end effector 324. The bores 312, 314, 318, and322 are substantially coaxially aligned and fluidically coupled.

A fluid line 302 is fluidically coupled to a proximal end of the innerlumen 308 and conducts a fluid 304 therethrough. The fluid line 302receives the fluid 304 from the fluid pump 64 and/or the fluidtemperature regulator 65. If the fluid 304 is used for cooling, thefluid 304 is conducted directly from the fluid pump 64 to the innerlumen 308 where it exits out of the distal end 36 of the end effector324. If the fluid 304 is used for heating or to maintain the endeffector 324 at a predetermined temperature, the fluid 304 is circulatedthrough the fluid temperature regulator 65 and then is conducted intothe lumen 308 by the fluid pump 64 either continuously orintermittently. The fluid line 302 is received through a housing portion306 of the instrument 300 and is fluidically coupled to the inner lumen308. The fluid 304 emanates or flows out from the distal end 326 of theend effector 324. The fluid 304 regulates the temperature of the endeffector 324 and/or the surrounding tissue in the surgical region ortarget site.

The generator 12 or a controller 67 (referred to hereinafter as thecontroller 67) comprise circuits that may be configured to control theoperation of the fluid pump 64 and/or the fluid temperature regulator65. The controller 67 receives a feedback signal that is a direct orindirect measure of the temperature of the end effector 324. In oneembodiment, as discussed in more detail below, the controller 67 may becoupled to a temperature sensor and receives a first feedback signalthat is directly indicative of the temperature of the end effector 324,the fluid 304 or other components of the instrument 300. In oneembodiment, as discussed in more detail below, the controller 67 may becoupled to the generator 12 and receives a second feedback signal thatis indirectly indicative of the temperature of the end effector 324, thefluid 304 or other components of the instrument 300. The controller 67is in electrical communication with (e.g., is electrically coupled to)the fluid pump 64. The controller 67 may control the operation of thefluid pump 64 and/or the fluid temperature regulator 65 either in anopen loop manner without employing the feedback signal; or in a closedloop manner by employing the feedback signal. In either implementation,the controller 67 may operate the fluid pump 64 and/or the fluidtemperature regulator 65 either continuously or intermittently to heat,cool, or otherwise regulate the temperature of the fluid 304, the endeffector 324, the tissue within the target site, and/or any othercomponent of the surgical instrument 300.

In one embodiment, the temperature of the ultrasonic end effector 324may be controlled or regulated by employing a end effector temperaturemeasurement signal as a feedback mechanism to the controller 67. Basedon the temperature feedback signal, the controller 67 controls theoperation of the fluid pump 64 and/or the fluid temperature regulator 65by conducting or infusing water or another cooling fluid 304 through thelumen 308 to control or regulate the temperature of the end effector 324to a predetermined temperature. Conducting or infusing the fluid 304 ata specified temperature keeps the end effector 324 at that temperatureand absorbs excess energy from the system that would otherwise desiccatethe tissue at the target site. The temperature of the end effector 324may be measured using frequency change of the system or by directmeasurement of the end effector or sheath temperature. In variousembodiments an acoustic sensor may be used to measure frequency. Endeffector temperature may be controlled by chilling the cooling fluid 304and conducting or infusing it through the end effector 324. The coolingfluid 304 may be employed to cool the ultrasonic end effector 324. Thecontroller 67 and/or the generator 12 may be employed to measure thefrequency changes of the end effector 324.

It is known that the frequency of the end effector 324 changes as afunction of the temperature of the end effector 324. Accordingly, it ispossible to approximate the temperature of the ultrasonic end effector324 during use by measuring the resonant frequency of the ultrasonictransducer 316 system. For example, the resonant frequency of theultrasonic transducer 316 system drops as the temperature of the endeffector 324 increases during use. In one embodiment, the controller 67and/or the generator 12 may be employed to detect the frequencyvariations of the ultrasonic transducer 316 system to derive an indirectmeasurement of the temperature of the end effector 324. The controller67 and/or the generator 12 may determine the temperature of the endeffector 324 based on the frequency feedback signal 71. The frequencyfeedback signal 71 is proportional to the temperature of the endeffector 324. Based on the frequency feedback signal 71, the controller67 controls the flow rate and/or the temperature of the fluid 304supplied to the surgical area or to the end effector 324 to regulate thetemperature of the end effector 324. The end effector 324 may be cooledby conducting fluid 304 at a lower temperature than the end effector 324through the end effector 324 or to the tissue at the target site eithercontinuously or intermittently to set and/or maintain a predeterminedtemperature. The indirect measurement of the temperature of the endeffector 324 based on the frequency variations of the ultrasonictransducer 316 system may be determined empirically by experimentationor design parameters and programmed into the ultrasonic signal generator12 or the controller 67 (e.g., in an integrated circuit within theinstrument). The temperature of the fluid or the frequency ofintermittent operation of the fluid pump 64 needed to maintain the endeffector 324 at a predetermined temperature also may be determinedempirically. The cooling fluid 304 may be conducted through the internallumen 308 or cannulas formed inside the instrument 300 at anypredetermined flow rate as may be necessary to keep the end effector 324at the prescribed temperature. In another embodiment, the fluid may beconditioned to a predetermined temperature by the fluid temperatureregulator 65 and then flowed through the inner lumen 308 at apredetermined flow rate to transfer any excess heat out of the system.

The irrigation lumen 308 formed within the body of the ultrasonic endeffector 324 also forms a fluidic conduit to provide relatively constantor intermittent irrigation to the target site. In one embodiment, theirrigation lumen 308 of the end effector 324 may be fluidically coupledto the irrigation pump 64 that is programmed for continuous orintermittent activation. The ultrasonic end effector 324 can be used fortissue cutting and/or hemostasis (e.g., coagulation). During thisprocess, the pump 64 remains shut-off or in a no-flow condition. Oncethe tissue load is removed from the end effector 324, the ultrasonicsignal generator 12 senses the no load condition and provides a feedbacksignal that indicates an operational state of the ultrasonic endeffector 324 to the controller 67 to control the pump 64 continuously orintermittently to supply the fluid 304 to the end effector 324 for aspecified period. In one embodiment, the fluid 304 may be a coolingfluid. As previously discussed, in one embodiment, the controller 67and/or the ultrasonic signal generator 12 may be adapted and configuredto sense the temperature of the end effector 324 by a referred orindirect measurement of the temperature based on the transducer 316system frequency. The fluid 304 may be conducted or infused continuouslyor intermittently to the end effector 324 until the end effector 324reaches a predetermined temperature.

In another embodiment, the ultrasonic signal generator 12 or thecontroller 67 may be adapted and configured to control the conduction orinfusion of the fluid 304 to the end effector 324 for a specified periodafter the operation of the end effector 324 is discontinued. In variousembodiments, the controller 67 may be adapted and configured to controlthe conduction or infusion of the fluid 304 to the end effector 324 whenthe ultrasonic signal generator 12 is not actively driving theultrasonic transducer 316. The conduction or infusion of fluid 304 maybe independent of any temperature or frequency feedback signals. Theconduction or infusion of fluid 304 may be, for example, for apredetermined amount of time and/or for predetermined repeating cycle.In another embodiment, the temperature of the end effector 324 may bemonitored during this period to control the temperature of the endeffector 324 to a specified temperature.

FIG. 9 illustrates a distal end of one embodiment of an ultrasonicinstrument 400 comprising a partial length inner lumen 408. Theultrasonic instrument 400 comprises a solid ultrasonic waveguide 402that is coupled to an ultrasonic transducer similar to the ultrasonictransducer 114 (FIG. 4) located in the direction indicated by arrow 404.The solid waveguide 402 is coupled to an end effector 410. The endeffector 410 and/or the waveguide 402 comprises an inlet port 406located at a node 412 to receive the fluid 304 from the fluid pump 64(FIG. 4) and/or the fluid temperature regulator 65 (FIG. 4) to a cool,heat, or otherwise control or regulate the temperature of the fluid 304and/or the end effector 410. The inlet port 406 is fluidically coupledto the partial length inner lumen 408. The fluid line 302 (FIG. 8) maybe fluidically coupled to the inlet port 406 at the node 412 to conductthe fluid 304 to the partial length inner lumen 408. A first portion ofthe partial length inner lumen 408 extends longitudinally through adistal end 414 of the end effector 410 where the fluid 304 emanates orflows out therefrom. A second portion extends of the partial lengthinner lumen 408 aslant or transverse from the first portion and througha lateral portion of the end effector 410. In the illustratedembodiment, the second portion extends transversely from the firstportion and extends through a lateral portion of the waveguide 402. Aspreviously discussed with reference to FIG. 8, the controller 67controls the operation of the fluid pump 64 and/or the fluid temperatureregulator 65 continuously or intermittently to heat, cool, or otherwiseregulate the temperature of the fluid 304 and/or the end effector 410.As discussed in more detail below, in yet another embodiment, thecooling fluid 304 may be conducted, infused, fed, or supplied eitherfrom a lumen formed within an outer sheath surrounding the waveguide 402or from the fluid inlet port 406 coupled to the sheath. Either of thesetechniques is suitable for conducting, infusing, spraying or otherwisechanneling the fluid 304 to an exterior portion of the end effector 324to control the temperature thereof.

FIG. 10 illustrates one embodiment of an ultrasonic instrument 500. FIG.11 illustrates a detail view of a distal end of the ultrasonicinstrument 500. With reference to FIGS. 10 and 11, the ultrasonicinstrument 500 comprises the instrument 300 discussed in FIG. 8 with anouter sheath 326 provided over the ultrasonic transmission waveguide320. As previously discussed, the ultrasonic instrument 300 comprisesthe transducer 316, the end effector 324, and the full length innerlumen 308. The outer sheath 326 is isolated from the waveguide 320 by aplurality of stabilizing silicone rings or compliant supports 328positioned at a plurality of nodes. The compliant supports 328 dampenundesirable vibration and isolate the ultrasonic energy from theremovable sheath 326 assuring the flow of ultrasonic energy in alongitudinal direction to the distal end of the end effector 324 withmaximum efficiency.

As previously discussed, the full length inner lumen 308 extends from aproximal end of the instrument 300 to a distal end of the end effector324 through the transducer 316 and the end effector 324. The lumen 308is fluidically coupled to the fluid line 302 to receive the fluid 304from the fluid pump 64 and/or the fluid temperature regulator 65 and toconduct the fluid 304 to the end effector 324. The fluid 304 emanates orflows out from the distal end 326 of the end effector 324 through thebore 322.

As previously discussed, the temperature of the end effector 324 may bemeasured directly or indirectly. In one embodiment, the temperature ofthe end effector 324 may be determined directly with a temperaturesensor, indirectly by measuring the operating frequency of the endeffector 324 and deriving the temperature, or using a combination ofthese techniques. The controller 67 receives either a temperaturefeedback signal 332 from a temperature sensor 330 (FIGS. 12, 13, 16-20,23, and 24), the frequency feedback signal 71, or a combination thereof,to determine the temperature of the end effector 324. The controller 67uses the feedback information to regulate the temperature of the endeffector 324 by controlling the flow rate and/or the temperature of thefluid 304. The temperature sensor 330 may comprise thermocouple orthermistor type devices, for example. To regulate the temperature of theend effector 324, the controller 67 controls the operation of the fluidpump 64 and/or the fluid temperature regulator 65 continuously,intermittently, or for a predetermined period, as previously discussed.In the illustrated embodiment, the temperature of the end effector 324may be measured indirectly by detecting variations in the operatingfrequency of the end effector 324 and providing the frequency feedbacksignal 71 to the controller 67. The controller 67 determines thetemperature of the end effector 324 based on the correlated frequencyfeedback signal 71 and controls the flow rate and/or the temperature ofthe fluid 304 supplied to the end effector 324 or the target site toregulate the temperature of the end effector 324. The controller 67 alsocontrols the operation of the fluid pump 64.

FIG. 12 illustrates one embodiment of an ultrasonic instrument 600. FIG.13 illustrates a detail view of a distal end of the ultrasonicinstrument 600. With reference to FIGS. 12 and 13, the ultrasonicinstrument 600 comprises the instrument 400 discussed in FIGS. 10 and 11and further comprises a temperature sensor 330 located within the outersheath 326 to measure the temperature of the end effector 324. Aspreviously discussed, the ultrasonic instrument 600 comprises thetransducer 316, the end effector 324, and the full length inner lumen308. The temperature sensor 330 provides a temperature feedback signal332 to the controller 67. Optionally, the temperature of the endeffector 324 may be measured by detecting the frequency of the endeffector 324 and providing the frequency feedback signal 71 to thecontroller 67. In the illustrated embodiment, the controller 67 maydetermine the temperature of the end effector 324 based on thetemperature feedback signal 332, or the frequency feedback signal 71, ora combination thereof. The controller 67 adjusts the flow rate and/orthe temperature of the fluid 304 supplied to the end effector 324 or thetarget site to regulate the temperature of the end effector 324 based onthe temperature feedback signal 332, the frequency feedback signal 71,or a combination thereof.

FIG. 14 illustrates one embodiment of an ultrasonic instrument 700. FIG.15 illustrates a detail view of a distal end of the ultrasonicinstrument 700. With reference to FIGS. 14 and 15, in one embodiment theultrasonic instrument 700 comprises a transducer 336, an end effector340 with a solid body, an outer sheath 342, and a cannula, lumen,conduit, or tube 344 located within the outer sheath 342. The endeffector 340, the ultrasonic waveguide 338, and the transducer 336comprise solid bodies with no inner lumen. The tube 344 may be locatedbetween the body of the ultrasonic waveguide 338 and the outer sheath342. The tube 344 is inserted through an opening 348 or inlet portformed in the outer sheath 342. The tube 344 is fluidically coupled tothe fluid line 302 and the fluid pump 64. The tube receives the fluid304 from the fluid pump 64. The temperature of the end effector 340 maybe measured indirectly by the generator 12 or the controller 67 bydetecting variations in the operating frequency of the end effector 340,providing the frequency feedback signal 71 to the controller 67, anddetermining the temperature of the end effector 340 based on thefrequency. The controller 67 receives the frequency feedback signal 71and determines the temperature of the end effector 340 based on thefrequency feedback signal 71. The controller 67 regulates thetemperature of the end effector 340 by controlling the flow rate and/ortemperature of the fluid 304 conducted to the end effector 340 and thetarget site until the end effector 340 reaches the desired temperature.The controller 67 may control the operation of the fluid pump 64 and/orthe fluid temperature regulator 65 either continuously orintermittently, as previously discussed, to regulate the temperature ofthe end effector 340. In the illustrated embodiment, the fluid issupplied through the tube 344. In other embodiments, however, the fluid304 may be conducted, fed, or supplied directly through the opening 348to a lumen formed within the outer sheath 342 or to the space betweenthe outer sheath 342 and the waveguide 338. Either technique is suitablefor conducting, spraying, or channeling the fluid 304 over the exteriorportion of the end effector 340 to control the temperature thereof.

FIG. 16 illustrates one embodiment of an ultrasonic instrument 800. FIG.17 illustrates a detail view of a distal end of the ultrasonicinstrument 800. The ultrasonic instrument 800 comprises the instrument700 discussed in FIGS. 14 and 15 and further comprises the temperaturesensor 330 located within the outer sheath 342 to measure thetemperature of the end effector 340. As previously discussed, theultrasonic instrument 800 comprises the transducer 336, the end effector340 with the solid body, the outer sheath 342, and the cannula, lumen,conduit, or tube 344 located within the outer sheath 342. The endeffector 340, the ultrasonic waveguide 338, and the transducer 336comprise solid bodies with no inner lumen. The tube 344 may be locatedbetween the body of the ultrasonic waveguide 338 and the outer sheath342. The tube 344 is inserted through an opening 348 or inlet portformed in the outer sheath 342. The tube 344 is fluidically coupled tothe fluid line 302 and the fluid pump 64. The tube 344 receives thefluid 304 from the fluid pump 64. The temperature sensor 330 providesthe temperature feedback signal 332 to the controller 67. In oneembodiment, the temperature of the end effector 340 may be measured bydetecting the frequency of the end effector 340 and providing thefrequency feedback signal 71 to the controller 67 to adjust the flowrate and/or temperature of the fluid 304 flowing into the target site toregulate the temperature of the end effector 340. In one embodiment, thetemperature of the end effector 324 may be determined using acombination of these techniques. Based on the temperature feedbacksignal 332, the frequency feedback signal 71, or a combination thereof,the controller 67 determines the temperature of the end effector 340,and regulates the temperature of the end effector 340 by controlling theflow rate and/or the temperature of the fluid 304 supplied to the endeffector 340 and target site with the fluid pump 64 and/or the fluidtemperature regulator 65 until the desired temperature is reached, aspreviously discussed. The fluid pump 64 and/or the fluid temperatureregulator 65 may be operated continuously or intermittently until thedesired temperature is reached. The fluid 304 may be fed, supplied, orconducted through the tube 344 formed within the outer sheath 342 andprovided through the opening 348. This technique also is suitable forspraying, conducting, or otherwise channeling the fluid 304 over theexterior of the end effector 340 to control the temperature thereof.

FIG. 18 illustrates one embodiment of an ultrasonic instrument 900comprising the transducer 316, a end effector 354, and a full lengthsealed inner lumen 352. The ultrasonic waveguide 320 is coupled to theultrasonic transducer 316 at the coupling connection or union/joint 328.The coupling connection 328 is substantially similar to the couplingconnection 70 discussed with reference to FIG. 2. The full length sealedinner lumen 352 extends from a proximal end of the instrument 300 to adistal end of the end effector 324 through the transducer 316 and theend effector 354. The sealed inner lumen 352 extends longitudinallythrough several sections of the instrument 300. The sealed inner lumen352 extends through a bore 312 formed through piezoelectric elements 310and a bore 314 formed through an ultrasonic transducer 316. The sealedinner lumen 352 further extends through a bore 318 formed within anultrasonic waveguide 320 and further extends through a bore 322 formedwithin the end effector 354. The distal end 326 of the end effector 354is sealed. The bores 312, 314, 318, and 322 are substantially coaxiallyaligned.

In one embodiment, the inner lumen 352 is filled with a phase changematerial 350. The phase change material 350 is sealed within the innerlumen 352. The phase change material 350 may comprise any material thatchanges from a solid or liquid phase to a gaseous phase. The phasechange material 350 controls the temperature of the end effector 354. Asthe phase change material 350 changes from a solid or liquid phase to agaseous phase it absorbs heat to maintain the end effector 354 at aspecified temperature. The phase change material 350 acts like a heatpipe material, absorbing heat at the end effector/tissue interface andreleasing the heat away from the interface. The heat pipe is a heattransfer mechanism that can transport large quantities of heat with avery small difference in temperature between the hot and coldinterfaces. A heat pipe may comprise a sealed hollow tube such as thesealed inner lumen 352. The waveguide 320 and the end effector 354 maybe formed of Ti6Al4V (an alloy of Titanium including Aluminum andVanadium), Aluminum, Stainless Steel, or other suitable materials, thathave thermoconductive properties. The pipe is formed of the waveguide320 and the end effector 354 comprising the inner sealed lumen 352filled with a relatively small quantity of the phase change material 350that acts as a “working fluid” or coolant (such as water, ethanol, ormercury). The rest of the pipe is filled with vapor phase of the phasechange material 350 or working fluid, all other gases being excluded.

In one embodiment, the temperature sensor 330 may be embedded in aninstrument sheath (e.g., the sheath 326 in FIG. 12) or the end effector354 to measure and correlate the temperature of the end effector 324.The temperature sensor 330 may comprise thermocouple or thermistor typedevices, for example.

FIG. 19 illustrates a distal end of one embodiment of an ultrasonicinstrument 1000 comprising a partial length sealed inner lumen 416. Theultrasonic instrument 1000 comprises a solid ultrasonic waveguide 402that is coupled to an ultrasonic transducer similar to the ultrasonictransducer 114 (FIG. 4) located in the direction indicated by arrow 404.The solid waveguide 402 is coupled to a end effector 418. The partiallength sealed inner lumen 416 may extend into the end effector 418region and/or the waveguide 402 region. The phase change material 350may be disposed within the partial length sealed inner lumen 416 in theend effector 418 and/or the waveguide 402 portions of the ultrasonicinstrument 1000. As previously discussed, the phase change material 350may comprise any material that changes from a solid or liquid phase to agaseous phase. The phase change material 350 is located inside thepartial length sealed inner lumen 416 to control the temperature of theend effector 418.

In one embodiment, the temperature sensor 330 may be embedded in aninstrument sheath (e.g., the sheath 326 in FIG. 12) or the end effector418 to measure and correlate the temperature of the end effector 418.The temperature sensor 330 may comprise thermocouple or thermistor typedevices, for example.

FIG. 20 illustrates one embodiment of a tissue welding apparatus 1100.The tissue welding apparatus 1100 may be employed to sever and weldtissue 1112. In one embodiment, the tissue welding apparatus 1100comprises a handle 1102, a shaft 1104, and a tissue welding end effector1106 pivotally connected to the shaft 1104 at pivot 1108. The placementand orientation of the tissue welding end effector 1106 may befacilitated by controls located on the handle 1102, including a rotationknob 1110 for rotating the shaft 1104 and the tissue welding endeffector 1106 about an axis. In one embodiment, the placement andorientation of the tissue welding end effector 1106 may be facilitatedby an articulation control for effecting the rotation, or articulation,of the end the effector 1106 with respect to the shaft 1104 about thearticulation pivot 1108. In various embodiments, the handle 1102 of thetissue welding apparatus 1100 may comprise a closure trigger 1114 and afiring trigger 1116 for actuating the tissue welding end effector 1106as described in greater detail below. It will be appreciated, however,that instruments having end effectors configured to perform differentsurgical tasks may have different numbers or types of triggers or othersuitable controls for operating the tissue welding end effector 1106.Furthermore, as previously discussed, it will be appreciated that theterms “proximal” and “distal” are used herein with reference to aclinician gripping the handle 1102 of the tissue welding apparatus 1100.Thus, the tissue welding end effector 1106 is distal with respect to thehandle 1102.

In the illustrated embodiment, the tissue welding end effector 1106 canbe configured to clamp, sever, and weld soft tissue, for example. Inother embodiments, different types of end effectors may be used such asgraspers, cutters, staplers, clip appliers, access devices, drug/genetherapy devices, ultrasound, RF and/or laser devices, for example. Thetissue welding end effector 1106 can include, among other things, anultrasonic tissue treating blade 1118 and a translatable clampingmember, such as an anvil 1120, for example, where the ultrasonic tissuetreating blade 1118 and the anvil 1120 can be relatively positioned, orspaced, in order to assure that the soft tissue 1112 clamped in thetissue welding end effector 1106 is properly welded and incised. Thehandle 1102 can include a pistol grip 1122 towards which a closuretrigger 1114 can be pivotally drawn in order to move the anvil 1120toward the ultrasonic tissue treating blade 1118 and clamp the tissue1112 positioned between the anvil 1120 and the ultrasonic tissuetreating blade 1118. Stated another way, once the clinician is satisfiedwith the positioning of the end effector 1106, the clinician may drawback the closure trigger 1114 to a position in which the anvil 1120 isfully closed and the closure trigger 1114 is locked into position.Thereafter, the firing trigger 1116 may be pivotally drawn toward thepistol grip 1122 to weld and sever the soft tissue 1120 clamped in theend effector 1106.

As shown in FIGS. 21 and 22 below, the tissue welding end effector 1106comprises an inlet line 1130 and an outlet line 1132. The inlet line1130 conducts the fluid 304 from the fluid pump 64 and/or the fluidtemperature regulator 65 to the tissue welding ultrasonic blade 1118. Astrong coagulation region may be achieved by maintaining the temperatureof the surface of the blade 1118 at a point between where coagulation ofthe tissue 1112 can occur and where desiccation of the tissue does notoccur. Lowering the temperature of the ultrasonic blade 1118 enables theblade 1118 to contact the tissue 1112 for a longer period. This enablesboth sides of the tissue 1112 in contact with the blade 1118 and acoaptation pad 1126 formed on the tissue clamping portion of the anvil1120 to form viable coagulation zones to improve the weld strength ofthe tissue 1112. As discussed below with reference to FIG. 24, inanother embodiment, the same blade 1118 cooling fluid may be flowedthrough the coaptation pad 1126 to increase the temperature of thetissue 1112 on the opposite side of the blade 1118.

FIG. 21 illustrates one embodiment of the end effector 1106 portion ofthe tissue welding apparatus 1100. The inlet line 1130 is fluidicallycoupled to the fluid pump 64 (FIG. 20) and receives fluid from the fluidpump 64. The inlet line 1130 is disposed beneath the blade 1118. Theoutlet line 1132 is fluidically coupled to either to the fluid pump 64and/or the fluid temperature regulator 65. The fluid is circulated bythe fluid pump 64. In one embodiment, the fluid may be heated by thefluid temperature regulator 65 prior to being circulated by the fluidpump 64 via the inlet line 1130.

FIG. 22 is a bottom view of the of the end effector 1106 portion of thetissue welding apparatus 1100 taken along line 22-22. With referencenow, to FIGS. 20-22, the tissue welding apparatus 1100 may be coupled tothe generator 12 to operate the tissue welding ultrasonic blade 1118.The tissue welding ultrasonic blade 1118 also may be coupled to theinlet line 1130 and the outlet line 1132. The fluid pump 64 isfluidically coupled to the inlet and the outlet lines 1130, 1132. Thepump 64 circulates the fluid through the inlet line 1130 and the outletline 1132. To heat the fluid, the fluid may be circulated to the fluidtemperature regulator 65. The controller 67 controls the operation ofthe fluid pump 64 and/or the fluid temperature regulator 65. The fluidis communicated from the fluid pump 64 to the blade 1118 via the inletline 1130 and the fluid returns either to the fluid pump 64 or to thefluid temperature regulator 65 via the outlet line 1132. In oneembodiment, the fluid may be heated by the fluid temperature regulator65 before it is pumped continuously or intermittently into the fluidinlet line 1130 by the fluid pump 64.

FIG. 23 illustrates one embodiment of a multi-element end effector 1140comprising an ultrasonic blade 1142 and a clamping mechanism 1144. Theultrasonic blade 1142 may be operated as previously described and willnot be repeated here for the sake of brevity. The clamping mechanism1144 is pivotally coupled to an elongated member or endoscopic portion1148 of an ultrasonic instrument. The clamping mechanism 1144 comprisesa clamp arm 1145 and a coaptation pad 1146. The clamping mechanism 1144is adapted to clamp tissue between the coaptation pad 1114 and theultrasonic blade 1142. The coaptation pad 1146 forms viable coagulationzones to improve the weld strength of the tissue.

In one embodiment, the clamp arm 1145 comprises an inner lumen 1150 toreceive a first fluid 1154 from a fluid pump 64 a. The fluid 1154 may beheated by a fluid temperature regulator 65 a prior to flowing throughthe lumen 1150. In one embodiment, the ultrasonic blade 1142 comprisesanother inner lumen 1152 to receive a fluid 1156 from a fluid pump 64 b.The fluid 1156 may be heated by a fluid temperature regulator 65 b priorto flowing through the lumen 1152. The fluids 1150, 1152 may be the sameor may be different fluids. The fluids 1150, 1152 may be supplied to thelumens 1150, 1152 from the same fluid source or from different fluidsources. For example, either one of the fluid pumps 64 a,b and/or eitherone of the fluid temperature regulators 65 a,b may supply the fluid toboth lumens 1152, 1150.

As previously discussed, while in use, the temperature of the ultrasonicblade 1142 may be approximated by measuring the resonant frequency ofthe ultrasonic system. As the temperature of the blade 1142 varies, theresonant frequency of the ultrasonic system also varies. For example, asthe temperature of the blade 1142 increases, the resonant frequency ofthe ultrasonic system decreases; and as the temperature of the blade1142 decreases, the resonant frequency of the ultrasonic systemincreases. Accordingly, the temperature of the blade 1142 may beinferred by measuring the deviation of the resonant frequency from areference frequency measured at a reference temperature point. In oneembodiment, the temperature of the blade 1142 may be inferred and thedeviation in the resonant frequency of the ultrasonic system may bemeasured and utilized to adjust the flow rate and/or temperature of thefluids 1154, 1156 flowing through the respective lumens 1150, 1152 intothe surgical area. This mechanism may be employed to adjust thetemperature of the blade 1142 and/or the coaptation pad 1146.

The actual frequency feedback mechanism and control required to maintainthe blade 1142 and/or the pad 1146 at a predetermined temperature may bedetermined empirically by experimentation or design parameters andprogrammed into the ultrasonic signal generator 12, in an integratedcircuit, or the controller 67, as previously discussed. The temperatureof either the pad 1146 and/or the blade 1142 may be controlled orregulated by flowing the respective fluids 1154, 1156 at predeterminedor desired temperatures. For example, the blade 1142 may be cooled byflowing the fluid 1156 that is colder than the temperature of the blade1142 as derived from the frequency measurement of the ultrasonic system.For example, the pad 1146 may be heated by flowing the fluid 1154 at atemperature that is higher than the temperature of the blade 1142 asderived from the frequency measurement of the ultrasonic system. Thefluids 1154, 1156 may be flowed through the pad 1146 and/or the blade1142 at a flow rate necessary to keep them at the predeterminedtemperature. In another embodiment, either one of the fluids 1154, 1156may be heated by the fluid temperature regulator 65 a,b to a desiredtemperature and then flowed through either one of the lumens 1150, 1152at a suitable rate to transfer heat energy into or out of the system.

In one embodiment, the temperature of the pad 1146 and/or the blade 1142may be measured with respective temperature sensors 1158, 1160. Thefirst and second temperature sensors 1158, 1160 may be thermocouple orthermistor type devices and may be embedded in the elongated member orendoscopic portion 1148 or sheath, the blade 1142, the pad 1146, and/orother suitable portions of the clamping mechanism 1144 such as the clamparm 1145, for example. The temperature sensors 1158, 1160 providerespective first and second temperature feedback signals 1162, 1164 tothe controller 67 to correlate temperature of the pad 1146 or the blade1142. In tissue welding applications, a strong coagulation area may beachieved by maintaining the temperature of the surface of the blade 1142at a point between where coagulation of the tissue can occur but wheredesiccation of the tissue does not occur. Lowering the temperature ofthe blade 1142 enables the blade 1142 to contact the tissue for a longerperiod. This allows for both the side of the tissue in contact with theblade 1142 and the side in contact with the coaptation pad 1146 to formviable coagulation zones, thus improving the weld strength of thetissue.

In one embodiment, the temperature of the ultrasonic blade 1142 or thecoaptation pad 1146 may be controlled by employing blade temperaturemeasurement as a feedback mechanism and infusing water or other fluids1154, 1156 at predetermined temperatures into the blade pad 1146 or theblade 1142 to maintain, regulate, or otherwise control theirtemperature. For example, infusing water at a specified temperature, ata specified flow rate, and for a specified period maintains the blade1142 at that temperature and absorbs excess energy from the system thatwould otherwise desiccate the tissue. The temperature of the pad 1146 orthe blade 1142 may be measured using either frequency change orvariation of the system or by direct measurement with the sensors 1162,1164. The temperature of the pad 1146 or the blade 1142 may be regulatedby infusing the fluids 1154, 1156 therethrough at a predeterminedtemperature. In one embodiment, the fluid 1156 may be employed to coolthe ultrasonic blade 1142 and to the fluid 1154 may be employed to heatthe coaptation pad 1146 side of the instrument.

FIG. 24 illustrates one embodiment of a multi-element end effector 1170comprising an ultrasonic blade 1172 and a clamping mechanism 1174. Theultrasonic blade 1172 may be operated as previously described and theoperation will not be repeated here for the sake of brevity. Theclamping mechanism 1174 is pivotally coupled to an elongated member orendoscopic portion of an ultrasonic instrument. The clamping mechanism1174 comprises a clamp arm 1176 and a coaptation pad 1178. The clampingmechanism 1174 is adapted to clamp tissue between the coaptation pad1178 and the ultrasonic blade 1172. The coaptation pad 1178 forms viablecoagulation zones to improve the weld strength of the tissue. In onembodiment, a fluid line 1180 is provided to receive a fluid 1182. Thefluid line 1180 is located in a body portion 1184 of the blade 1172. Thefluid line 1180 is then routed through the clamp arm 1176 and is locatedadjacent to the coaptation pad 1178. The fluid 1182 exits through anoutlet port 1186 from the clamp arm 1176. Thus, the same blade coolingfluid 1182 is routed through the coaptation pad 1178 to increase thetemperature of the tissue on the side opposing the blade 1172.

FIG. 25 is a diagram 1200 illustrating the operation of variousembodiments of the ultrasonic instruments described herein employing anexternal temperature measurement device. In one embodiment, thetemperature measurement device may comprise the temperature sensor 330to provide a temperature feedback signal 332 to the controller 67 asdescribed above with respect to FIGS. 12, 13, 16-20, 23, and 24. Thetemperature feedback signal 332 is provided to the controller 67 toregulate the fluid pump 64 and/or the fluid temperature regulator 65.The surgical procedure is initiated when the operator (e.g., thesurgeon) triggers 1202 the triggering mechanism 44 to activate 1204 thegenerator 12. The operator employs the ultrasonic instrument to transect1206 tissue. During the procedure, the elements of the ultrasonic systemsuch as the generator 12 or the controller 67 monitor 1208 thetemperature change of the ultrasonic blade by monitoring the temperaturefeedback signal 332 from the temperature sensor 330 located in proximityto the end effector. In one embodiment, the temperature sensor 330 maybe located in the clamp arm assembly, embedded in the blade, or locatedwithin the sheath, or in proximity thereto. Based on the temperaturefeedback signal 332, the controller 67 operates the fluid pump 64continuously or intermittently to pump fluid through the blade tomaintain or regulate the temperature of the blade. To terminate thesurgical procedure, the operator releases 1212 the triggering mechanismand deactivates 1214 that generator 12. The fluid pump 64 continues topump fluid through the blade for a predetermined period or until theblade reaches a predetermined temperature. It is appreciated that invarious embodiments fluid will not be pumped through the end effectorsuntil the generator has been deactivated.

FIG. 26 is a diagram 1300 illustrating the operation of variousembodiments of the ultrasonic instruments described herein employing afrequency shift temperature measurement technique. In one embodiment,the frequency shift temperature measurement technique may be employed toderive the temperature of the ultrasonic blade based on the shift inresonant frequency generally attributed to the change in the temperatureof the blade. These techniques employ the frequency feedback signal 71as previously discussed with reference to FIGS. 8 and 10-17. Thefrequency shift may be measured by the generator 12 or the controller67. The frequency feedback signal 71 is provided to the controller 67 toregulate the fluid pump 64 and/or the fluid temperature regulator 65.The surgical procedure is initiated when the operator (e.g., thesurgeon) triggers 1302 the triggering mechanism 44 to activate 1304 thegenerator 12. The operator employs the ultrasonic instrument to transect1306 tissue. During the procedure, the elements of the ultrasonic systemsuch as the generator 12 or the controller 67 monitor 1308 thetemperature change of the ultrasonic blade by monitoring the frequencyfeedback signal 71, which is proportional to the temperature of theultrasonic blade. Based on the temperature feedback signal 332, thecontroller 67 operates the fluid pump 64 continuously or intermittentlyto pump fluid through the blade to maintain or regulate the temperatureof the blade. To terminate the surgical procedure, the operator releases1312 the triggering mechanism and deactivates 1314 that generator 12.The fluid pump 64 continues to pump fluid through the blade for apredetermined period or until the blade reaches a predeterminedtemperature. It is appreciated that in various embodiments fluid willnot be pumped through the end effectors until the generator has beendeactivated.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

FIGS. 7A, 7B, and 20-24 illustrate various embodiments comprising bladesand clamp arm assemblies comprising proximal tissue pad segments, distaltissue pad segments and tissue pad insert segments. The pivotal movementof the clamp arm assemblies with respect to the blades may be affectedby the provision of a pair of pivot points on the clamp arm portion ofthe clamp arm assembly that interfaces with an ultrasonic surgicalinstrument via weld pin fastening or other fastening means (not shown).The tissue pad segments may be attached to the clamp arm by mechanicalmeans including, for example, rivets, glues, adhesives, epoxies, pressfitting or any other fastening means known in the art. Furthermore, thetissue pad segments may be removably attached to the clamp arm by anyknown means.

In various embodiments, the clamp arm may comprise a T-shaped slot foraccepting a T-shaped flange of a proximal tissue pad segment, a distaltissue pad segment and a tissue pad insert segment. In variousembodiments, a single unitary tissue pad assembly may comprise theproximal tissue pad segment, the distal tissue pad segment and thetissue pad insert segment, and further comprise a T-shaped flange forreception in a T-shaped slot in the clamp arm assembly. Additionalconfigurations including dove tailed-shaped slots and wedge-shapedflanges are contemplated. As would be appreciated by those skilled inthe art, flanges and corresponding slots have alternative shapes andsizes to removably secure the tissue pad segments to the clamp arm.

A method for replacing the proximal tissue pad segment, the distaltissue pad segment and/or the tissue pad insert segment include one ormore of the steps of: a) disengaging the clamp arm assembly from theultrasonic surgical instrument; b) removing at least one of the tissuepad segments from the clamp arm; c) inserting at least one new orreconditioned tissue pad segment into the clamp arm; and d) engaging theclamp arm assembly with the ultrasonic surgical instrument. In thisremoval and replacement process, the new or reconditioned proximaltissue pad segment, distal tissue pad segment and tissue pad insertsegment may be multiple separate segments or of unitary construction.

Another method for replacing the proximal tissue pad segment, the distaltissue pad segment and/or the tissue pad insert segment include one ormore of the steps of: a) opening flanges on the clamp arm; b) removingat least one of the tissue pad segments from the clamp arm; c) insertingat least one new or reconditioned tissue pad segment into the clamp arm;and d) closing flanges on the clamp arm. In this removal and replacementprocess, the new or reconditioned proximal tissue pad segment, distaltissue pad segment and tissue pad insert segment may be multipleseparate segments or of unitary construction.

Preferably, the various embodiments described herein will be processedbefore surgery. First, a new or used instrument is obtained and ifnecessary cleaned. The instrument can then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK® bag. The container and instrumentare then placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high-energy electrons.The radiation kills bacteria on the instrument and in the container. Thesterilized instrument can then be stored in the sterile container. Thesealed container keeps the instrument sterile until it is opened in themedical facility.

It is preferred that the device is sterilized. This can be done by anynumber of ways known to those skilled in the art including beta or gammaradiation, ethylene oxide, steam.

Although various embodiments have been described herein, manymodifications and variations to those embodiments may be implemented.For example, different types of end effectors may be employed. Inaddition, combinations of the described embodiments may be used. Forexample, a concave blade tip may be coated with a hydrophobic material.Also, where materials are disclosed for certain components, othermaterials may be used. The foregoing description and following claimsare intended to cover all such modification and variations.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed is:
 1. A surgical instrument, comprising: a transducerconfigured to produce vibrations at a predetermined frequency; anultrasonic end effector extending along a longitudinal axis coupled tothe transducer, wherein the ultrasonic end effector comprises anultrasonic blade and a clamping mechanism; a controller configured toreceive a feedback signal from an external surface of the ultrasonic endeffector at a single position which is distal relative to thetransducer, wherein the feedback signal is measured by the controller; apump, wherein the pump comprises a fluid and wherein the pump iscontrolled by the controller; a lumen adapted to couple to the pump,wherein the controller is configured to control fluid flow through thelumen based on the feedback signal, and wherein the lumen is locatedwithin the ultrasonic end effector; and a fluid temperature regulator,wherein the fluid temperature regulator is configured to adjust atemperature of the fluid within the pump, and wherein the fluidtemperature regulator is controlled by the controller.
 2. The surgicalinstrument of claim 1, comprising an ultrasonic transmission waveguideextending longitudinally and coupled between the transducer and theultrasonic blade, wherein the lumen extends longitudinally through theultrasonic transmission waveguide.
 3. The surgical instrument of claim1, wherein the lumen extends longitudinally through at least one of theultrasonic blade or the clamping mechanism or a combination thereof. 4.The surgical instrument of claim 1, wherein the lumen comprises a firstand a second lumen, wherein the first lumen extends through theultrasonic blade and the second lumen extends through the clampingmechanism.
 5. The surgical instrument of claim 1, comprising anultrasonic transmission waveguide extending longitudinally and coupledbetween the transducer and the ultrasonic blade, wherein the lumenextends longitudinally and transversely through the ultrasonic blade anda portion of the ultrasonic transmission wave guide and extendslaterally to an edge of the ultrasonic transmission waveguide and isfluidically coupled to an inlet port formed at a node of the ultrasonictransmission waveguide.
 6. The surgical instrument of claim 1, whereinthe feedback signal is a direct or indirect measure of a temperature ofthe ultrasonic end effector.